Point-detonating fuse for projectiles



Feb. 11, 1936. WOQDBERRY 2,030,085

POINT DETONATING FUSE FOR PROJEGTILES Filed Feb. 7, 1934 2 Sheets-Sheet 2 g 6 INVENTOR.

DAV/0 L. WOOOBEPEY BY O W3 0%, f.

/0 ATTORNEY.

Patented Feb. 11, 1936' POINT-DETONATING FUSE FOB PROJECTILES.

David L. Woodberry, scum Arsenal, Md. Application February "I, 1934, Serial No. 710,064

7 Claims.

(Granted under the m of March a, 1883, as

amended April 30, 1928; 370 0. (5. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to and impacts nose first.

' Another object of this invention is to provide a point-detonating fuse having the detonator out of alignment with the firing pin and the bursting charge until the projectile to which the fuse is assembled is ejected from the muzzle of the piece and set-back force ceases to a degree where the spring under the firing pin will cause the firing pin to move forward releasing the detonator carrier, which then due to centrifugal force, and, or spring action, slides over and aligns the detonator with the firing pin and the bursting charge.

A further object of this invention is to provide a point-detonating fuse having a firing pin safely locked against movement prior to being ejected from the piece.

A still further object of this invention is to provide apoint-detonating fuse having a firing pin safely locked against movement until ejected from the piece and set-back force ceases.

Another object of this invention is to provide a point-detonating'fuse havinga-base which may be varied in dimensions to fit into the nose of shell with varying openings.

Still another object-of this invention is to provide a fuse that will not function or cause the projectile to burst in the event that ranges under 300 yards are obtained with the projectile.

With these and other objects in view which may be incident to my improvements, this invention consists in parts and combinations to be hereinafter set forth and claimed with the understanding that the necessary elements comprising my invention'may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in accompanying drawings means for carrying the same into prac-, tical effect without limiting the improvements in their useful applications to the particular constructions, which for the purpose of explanation, have been made the subject of illustration. In the drawings forming a part of this specificaion: 1 1

Figure l is a longitudinal sectional view of the fuse fully loaded and assembled ready to be further assembled into the nose of a projectile.

Figure 2 is sectional view of the fuse taken on line 2-2 of Figure 1, showing the position of the shear-wire before being fired from the piece.

Figure 3 is a sectional view of the fuse taken on line 33, of Figure 1, showing the position of the detonator carrier, detonator, lock pin, and guide pin, before firing from the'piece.

Figure 4 is a longitudinal part sectional view showing the position of the firing'pin, safety pin, and firing pin stop, before firing from the piece.

Figure 5 is a longitudinal sectional view of the fuse assembled to a projectile being ejected from the piece showing the retaining ring in the setback position freeing the two steel balls.

Figure 6 is a longitudinal sectional view of the '25 fuse and the projectile in flight showing the retainer ring in the set-back position, the bails out into the groove of the retaining ring, the firing pin in the forward position, the detonator carrier in the armed and locked position aligning the detonator with the firing pin and bursting charge.

Figure 7 is a sectional view of the fuse taken on line 1-1 of Figure 6 showing the detonator carrier in the armed and locked position, while in. flight. I

FigureB is a longitudinal sectional view of the fuse on impact showing the firing pin driven into the detonator which initiates the functioning of. the bursting charge.

Figure 9 is a sectional view similar to Figure 1 of a slightly modified form of fuse for use with projectiles fired from smooth bore guns.

Figure 10 is a section similar to Figure 9 of a modified form.

Referring more particularly by numerals to the drawings in which the same and similar elements are designated by like symbols of reference throughout, and more particularly to Figure 1, the fuse body I is formed at the top with a truncated head portion 2 and at the bottom with a downward projecting neck 3. The head portion 2 is provided with a horizontal bore 4 and a vertical bore 5 of smaller varying diameters. The bore 4 is closed at one end and opens into one face of the fuse head at the other, while the bore 8 66 opens into the nose at one end and communicates with the bore 4 at the other.

The neck 3 is provided with a vertical bore 6 opening in the bottom thereof at one end and communicating-at the other with the smaller borev I opening into the horizontal bore 4, the same corresponding with and being in alignment with the vertical bore 5 opening into the other side thereof. .The horizontal bore 4 in the head is extended to the outer portion of the fuse by a constricted bore. The nose of the fuse body I is provided with a centrally located annular groove 9. A firing pin l0 having an integral point II is adapted to be fitted into the vertical bore 5. The outer end of the firing pin is provided with a disk head l2, formed as an integral part thereof or as a separate part suitably fixed thereto. Disk head I2 normally rests against the forwardend of the fuse body I, and is held in this position before firing by two steel balls l3 and I4, the balls being held in position by a retainer sleeve |5.. Sleeve I5 is slidably received in annular groove 9 of fuse body I and held in advanced position by a shear wire I6 and safety pin I1 extending therethrough and through corresponding openings in fuse body Steel balls I3 and I4 seat into annular grooves on opposite sides of firing pin I0 and with the sleeve l5 inthe upper position shown in Figure 1 these balls may not move outwardly, thus locking firing pin i0 in" lowered position. By removing safety pin I1 and by shearing wire l6, retaining sleeve I5 is free to move downwardly into groove 9 so as to free balls i3 and I4,'thus freeing firing pin l0.

Shear wire I 6 is adapted to be sheared ofl upon set-back, that is, by the very rapid forward movement of the shell when fired, causing'the sleeve |5 to move downward in its groove 9.

In order to protect personnel firing shells having this'fuse mechanism, and those in an advanced position over whose heads the shells are .to be fired, the shear wire I6 is so designed that it will notshearoflz when the set-back force is less than a predetermined amount. Thus the wire l6 and the weight of sleeve I5 may be so designed that for rangesunder 300 yards the "set-back will be insufficient toshear wire l6, so that if for any reason the propellent charge is defective or insufiicient the shell will not arm and can not explode.

Firing pin I0 is urged forward, to armed position, by -a spring I8 seated in socket 5, but pin I0 is locked in lowered position by balls I3 and I4. Positioned within the cross bore'4 is a detonator carrier 20 having a vertical aperture extending therethrough near one end for carrying a detonator charge 2|. Can'ier 20 has a vertical aperture 22 extending about half-way through the central portion thereof, this opening 22 and the opening for detonator charge 2| communicating at their upper ends with a longitudinal slot 23 in carrier 2|]. Slot 23 decreases in depth toward its right hand end as seen'in Figure 1, and is narrower than firing pin III, the aperture 22 and opening for charge 2| continuing through slot 23 as grooves (see Figure 6). Aperture 22 is adapted to receive the lower end of firing pin II! to lock detonator carrier 20 in safe position as long as the firing pin is locked by balls I3 and I4 and sleeve l5. After insertion of carrier 20, the cross bore 4 is closed by screw cap 24.

Cross bore 4 is constricted at one end to provide ashoulder 25 fonengagement by a corresponding shoulder 26 on carrier 20, to limit outward movement of the carrier. Referring to Figures 3 and 7, carrier 20 has an aperture 21 in which is seated a movable pin 28 slightly shorter than the aperture. The shell body has an aperture 29 into which pin 28 moves after carrier 20 has moved to firing position.

Opposite aperture 29, carrier 20 is provided with a longitudinal slot 30 into which projects the inner end of guide pin 3|. Pin 3| is threaded into shell body I in alignment with aperture 29, to facilitate machining. Guide pin 3| allows free reciprocation of carrier 20 but prevents rotation thereof, thereby maintaining pin 28 in alignment with opening 29 and charge 2| in alignment with firing pin l0. Accidental shearing of wire I6 during shipping and handling of the shell is prevented by the removable pin I! which passes through sleeve I5, fuse body I, and firing pin I0, Thus prior to removal of safety pin I! the firing pin I0 is locked down by-balls I3 and I4 and pin l1, thus locking charge carrier 20 in the safe position by engagement of the lower end of firing pin ID in aperture 22 of carrier 20. Removal of safety pin II prior to firing is facilitated by pull ring 32 secured thereto. I

The restricted vertical bore I, Figure 1, communicating with cross bore 4 contains an explosive' train 33 in contact with a bursting charge within a tube 34, the tube 34 being screw-threaded into bore 6 of base 3 of shell body I.

As seen in Figure 4, the head 2 of fuse I has a screw threaded aperture communicating with bore 5 in which is threaded a bolt 36 having its inner end 31 fitting into a longitudinal groove 38 in firing pin III to limit outward movement of the firing pin. Sleeve I5 has a slot 39 for receiving the head of bolt 36, thus preventing rotation of sleeve I5 thus facilitating assembly since the opening in this sleeve must align with those in shell body to receive shear pin |6 and safety pin II.

After the fuse has been assembled the neck 3 is screwed into a shell 4| (Figure 5). Shell 4| is adapted to be fired from a rifled barrel, since the safety devices are released by rotation of the shell in flight. The invention is illustrated in connection with shell for a chemical mortar, i. e., wherein the shell has a propellent charge secured to its base and is dropped into the muzzle of the mortar, but it may obviously be used with any rotating shell.

The operation of the invention is as follows. After assembly of the fuse the neck 3 is screwed into the end of the shell 4| (Figure 5), the parts being in the position shown in Figure 1. Premature firing cannot occur due to the various safety features, the charge carrier 20 being held with the charge 2| out of alignment with explosive train33 by engagementof the lower end of firing pin ID in opening 22; firing pin I0 is locked down in same position by steel balls I3 and I4 and by safety pin I'I; balls I3 and M are locked by sleeve I5; and sleeve I5 is locked in upper safe position by pin I1 and shear wire Hi.

When the shell is to be fired, safety pin I1 is withdrawn. However, the parts are still locked in safe position by shear wire I6. The shell is now fired, in the case of the mortar, by dropping the same in the open end of the barrel, and the rapid forward acceleration causes the sleeve I5 to move backward in its slot, thus shearing off wire l6. As previously pointed out, if the range of the shell is less than a predetermined minimum, this setback force willbe insumcientto shear wire I6 out of alignment with the firing pin, means operable by initial acceleration of the shell when fired to break said shear member and release said firing pin, and means operable upon a" predetermined decrease in acceleration to move said firing pin to release said transversely movable member.

2. An impact fuse for rotating shells comprising a fuse body, a bursting charge carried thereby, a transversely movable member, a detonator charge on said member, a longitudinally movable firing pin, means including a shear element normally holding said firing pin in interlocked engagement with said transversely movable member, said means being released upon initial acceleration of the shell when fired, and means for moving said transversely movable member to armed position with the detonator charge aligned with the firing pin during flight of the shell, all parts of the fuse and safety mechanism remaining attached to. the fuse during flight whereby the balance of weight is maintained and accuracy of fire is increased.

3. An impact fuse for shells comprising a fuse body having a base adapted for attachment to a shell, a bursting charge on said fuse body, .a longitudinally slidable firing pin, a transversely movable member carrying a detonator charge, safety mechanism including a shear element for holding said firing pin and transversely movable member in unarmed position, and means for arming said fuse in flight, all movable parts of said fuse being positioned in the nose of the fuse whereby the base of the fuse may be adjusted to varying sizes of shell.

4. An impact fuse for shells comprising a fuse body, a bursting charge carried thereby, a transversely movable member carrying a detonator charge, a longitudinally movable firing pin adapted to interlock with the transversely movable member to hold the same in safe position, a spring tending to move said firing pin to armed position,

detent means holding said firing pin interlocked with said member, means to release said detent means by initial acceleration of the shell when fired, and means to limit transverse movement of said member when released by the firing pin to cause alignment of the detonator charge and firing pin, the end of the transverse member being out of contact with the barrel of the gun.

5. An impact fuse for projectiles comprising a fuse body, a bursting charge carried thereby, a transversely slidable member carrying a detonator charge, a longitudinally movable firing pin adapted to engage the slidable member and lock the same in safe position, a spring biasing said firing pin forwardly to release said transversely slidable member, detent means retaining said firing pin in safe position, a longitudinally slidable sleeve locking said detent. means in engagement with said firing pin, and a shear member retaining said sleeve in position and breakable upon initial linear acceleration of the projectile.

6. The invention as described in claim 5 wherein the detent means comprises a plurality of balls, said longitudinally slidable sleeve allowing release of said balls but retaining them on the fuse body.

7. An impact fuse for projectiles comprising a fuse body, a bursting charge carried thereby, a

longitudinally slidable firing pin, a transversely DAV-ID L. WOODBERRY. 

